This invention relates generally to the field of telephony, and more particularly to improved multi-subscriber interface hardware for the purpose of providing security and prevention of environmental contamination.
In a typical installation in a multi-tenant building, a building entrance terminal with twenty-five or one hundred subscriber pairs interconnected thereto is usually mounted upon a building wall, commonly at a basement level. Although a part of the terminal housing is available only to telephone company personnel, of necessity, a second part containing the commonly used R.J. 11 plug is available to the subscribers who connect their equipment, and may remove it for testing.
Such a location lends itself to theft of telephone services, either by unscrupulous tenants who connect their equipment to the lines of other subscribers, or by those who make such interconnection without any legal association with the building. All that is required is the disconnection of a given subscriber equipment plug, and the connection of a telephone handset using a similar plug in an existing jack. It is also desirable to a telephone users to be able to preclude unauthorized persons from having free access to their individual telephone line. Structure for accomplishing this end is most conveniently provided at the location of a standard telephone wall plate outlet or other similar industry standard telephone connection device which contains an R.J. 11 receptacle or similar hardware. It is also desirable that such structure may include such circuitry as a maintenance termination unit or noise suppression and radio filtering circuitry most conveniently accommodated behind the R.J. 11 type jack.
In the above-identified copending application, there is disclosed a device which selectively covers or exposes the opening in an individual subscriber R.J. 11 receptacle by means of a sliding cover plate, together with means for locking the relative position of the plate and the receptacle as desired. The disclosed device includes an alpha-numeric combination locking device which will fix the position of the sliding cover in any of three predetermined relative locations. This construction, while useful, does add to the cost of installation of an individual subscriber circuit which increase cannot always be justified and/or cannot be passed on as a fixed cost to the subscriber.